2016/12/21 by Fabio Panza, Michail Osipenko, Panza, Fabio +8
Engineering · Medicine · Physics and Astronomy · #Computational Physics (physics.comp-ph) #FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det) #Nuclear Physics and Applications #Nuclear reactor physics and engineering #Radiation Detection and Scintillator Technologies #Radiation Therapy and Dosimetry
paper · pdf · doi:10.48550/arxiv.1612.07009
openalex publication_date 2016/12/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this paper we simulated the behavior of a simple ADS model, based on MOX\nfuel embedded in solid lead, in terms of multiplication coefficient keff,\nthermal power and absolute neutron spectra. In the first part of the paper, we\nreport on the results obtained when modifying the reflector surrounding the\nfission core, by replacing pure lead with a layered graphite/lead structure. We\nfound that, by appropriately choosing position and thickness of the graphite\nand lead layers, it is possible to obtain a hybrid system where the neutron\nspectrum in the core still exhibits a fast character, while the spectrum in the\ngraphite layer is considerably softer, becoming thermal in the most peripheral\npositions. In order to obtain such a modulation of the neutron spectra from the\ncenter of the system to the periphery, a careful choice of the materials has to\nbe made in order to avoid large variations of the local power at the core\nboundary. However, the smoothness of the power distribution is obtained at the\nexpense of lower values of keff and the total power of the system. In the\nsecond part of the paper, we explored the option of adopting light water as\ncoolant, instead of the helium gas assumed in the initial design. We found that\nthis produces an increase in keff and thermal power, without significantly\nperturbing the fast character of the system and without introducing spatial\npower excursions in any place within the core. The characteristics obtained may\nallow to design a system where fast, mixed and thermal spectra can be used to\nexpand the use of the ADS as an irradiation facility.\n